Segments in this Video

Part A: Introduction(01:05)

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Sir Issac Newton's first law of motion explains that objects will remain at rest or in motion with the same speed and direction unless acted on by an unbalanced force. His second law of motion allows scientists to calculate how large a force must be to accelerate an object by a certain amount.

Part B: Fnet= ma(10:30)

Force and acceleration are proportional; mass and acceleration exhibit an inverse relationship. The net force is the sum of all the forces. Spiro Liacos demonstrates several examples of using the equation.

Part C: Friction and Mass(04:37)

Friction can increase with heavier objects, but wheels help eliminate friction. Small forces cause small accelerations. Liacos describes why objects barely move when frictional forces on objects are too small.

Part D: Newton's Second Law of Car Motion(05:45)

Acceleration is determined by the ratio of force that it can generate to its mass. Liacos describes why trucks accelerate more slowly than drag racing vehicles and why cars have safety precautions to slow down an impact such as steel beams, airbags, and seatbelts.

Part E: Free Fall Accelerate(10:53)

All objects accelerate at 9.8 meters per second per second regardless of mass. Liacos demonstrates how the force of gravity equals the mass times 9.8 newtons per kilogram and how air resistance affects acceleration. Terminal Velocity occurs when the resistance of the medium through which an object is falling prevents further acceleration.

Part F: Mass and Weight(06:30)

In physics, mass is the amount of matter in the object, while weight is the force of gravity pulling the object downwards. Learn how weight and forces needed to move objects change in different atmospheres. In the next episode, viewers will learn about Newton's third law of motion.

Description

In episode seven of the Shedding Light on Motion series, we answer the most important question that has ever been asked: how does a magician pull a tablecloth out from under a dinner set? No, seriously, we look at the so simple and yet so powerful equation F = ma. Newton’s Second Law tells us how to calculate the amount of force required to accelerate something by a given amount.